Method for the preparation of trimethylhydroquinone

Abstract

Trimethylhydroquinone is prepared by reacting 4-methoxyphenol with methanol over MgO or MgO promoted with oxides of aluminum, uranium, titanium, cerium, manganese, zinc, and iron at temperatures of from about 350° C to about 550° C and pressures up to about 1,000 pounds per square inch gauge.

I claim: 
     
       1. A method for the production of trimethyhydroquinone comprising reacting 4-methoxyphenol with methanol over catalysts selected from the group consisting of magnesium oxide and aluminum oxide at temperatures of from about 350° C to about 550° C at pressures of from about atmospheric to about 1,000 psig. 
     
     
       2. A method as described in claim 1 above wherein addition the catalysts are promoted with oxides of uranium, titanium, cerium, manganese, zinc and iron. 
     
     
       3. A method as described in claim 2 above wherein the 4-methoxyphenol contains up to about 25 weight percent hydroquinone. 
     
     
       4. A method as described in claim 2 wherein the mole ratio of 4-methoxyphenol to methanol ranges from about 0.05 to about 4. 
     
     
       5. A method as described in claim 4 wherein the reaction is carried out in a continuous flow reactor. 
     
     
       6. A method as described in claim 5 wherein the LHSV is from about 0.1 to about 50. 
     
     
       7. A method as described in claim 2 wherein the by-products of the reaction are separated and recycled for inclusion with 4-methoxyphenol feed. 
     
     
       8. A method as described in claim 2 wherein up to about 15 weight percent water is present in the feed, based upon the total feed weight. 
     
     
       9. A method as described in claim 2 wherein the trimethylhydroquinone produced in 2,3,6-trimethylhydroquinone, the catalyst is magnesium oxide, the reaction pressure is from about 200 to about 500 pounds per square inch gauge. 
     
     
       10. A method as described in claim 9 wherein the reaction is carried out continuously at a liquid hourly space velocity from about .2 to about 10. 
     
     
       11. A method as described in claim 10 wherein in addition the feed stream contains up to about 15 weight percent water based upon the total feed weight.